package org.go.trigger.calendar;

import java.util.TimeZone;

import org.go.trigger.Calendar;

/**
 * <p>
 * This implementation of the Calendar excludes a set of days of the week. You
 * may use it to exclude weekends for example. But you may define any day of
 * the week.  By default it excludes SATURDAY and SUNDAY.
 * </p>
 *
 * @see org.quartz.Calendar
 * @see org.go.trigger.calendar.BaseCalendar
 *
 * @author Juergen Donnerstag
 */
public class WeeklyCalendar extends BaseCalendar {
	static final long serialVersionUID = -6809298821229007586L;

	// Will be set to true, if all week days are excluded
	private boolean excludeAll = false;

	// An array to store the week days which are to be excluded.
	// java.util.Calendar.MONDAY etc. are used as index.
	private boolean[] excludeDays = new boolean[8];

	public WeeklyCalendar() {
		this(null, null);
	}

	public WeeklyCalendar(Calendar baseCalendar) {
		this(baseCalendar, null);
	}

	public WeeklyCalendar(Calendar baseCalendar, TimeZone timeZone) {
		super(baseCalendar, timeZone);

		excludeDays[java.util.Calendar.SUNDAY] = true;
		excludeDays[java.util.Calendar.SATURDAY] = true;
		excludeAll = areAllDaysExcluded();
	}

	public WeeklyCalendar(TimeZone timeZone) {
		super(null, timeZone);
	}

	/**
	 * <p>
	 * Check if all week days are excluded. That is no day is included.
	 * </p>
	 *
	 * @return boolean
	 */
	public boolean areAllDaysExcluded() {
		return isDayExcluded(java.util.Calendar.SUNDAY) && isDayExcluded(java.util.Calendar.MONDAY) && isDayExcluded(java.util.Calendar.TUESDAY) && isDayExcluded(java.util.Calendar.WEDNESDAY) && isDayExcluded(java.util.Calendar.THURSDAY)
				&& isDayExcluded(java.util.Calendar.FRIDAY) && isDayExcluded(java.util.Calendar.SATURDAY);
	}

	@Override
	public Object clone() {
		WeeklyCalendar clone = (WeeklyCalendar) super.clone();
		clone.excludeDays = excludeDays.clone();
		return clone;
	}

	/**
	 * <p>
	 * Get the array with the week days
	 * </p>
	 */
	public boolean[] getDaysExcluded() {
		return excludeDays;
	}

	/**
	 * <p>
	 * Determine the next time (in milliseconds) that is 'included' by the
	 * Calendar after the given time. Return the original value if timeStamp is
	 * included. Return 0 if all days are excluded.
	 * </p>
	 *
	 * <p>
	 * Note that this Calendar is only has full-day precision.
	 * </p>
	 */
	@Override
	public long getNextIncludedTime(long timeStamp) {
		if (excludeAll == true) {
			return 0;
		}

		// Call base calendar implementation first
		long baseTime = super.getNextIncludedTime(timeStamp);
		if ((baseTime > 0) && (baseTime > timeStamp)) {
			timeStamp = baseTime;
		}

		// Get timestamp for 00:00:00
		java.util.Calendar cl = getStartOfDayJavaCalendar(timeStamp);
		int wday = cl.get(java.util.Calendar.DAY_OF_WEEK);

		if (!isDayExcluded(wday)) {
			return timeStamp; // return the original value
		}

		while (isDayExcluded(wday) == true) {
			cl.add(java.util.Calendar.DATE, 1);
			wday = cl.get(java.util.Calendar.DAY_OF_WEEK);
		}

		return cl.getTime().getTime();
	}

	/**
	 * <p>
	 * Return true, if wday (see Calendar.get()) is defined to be exluded. E. g.
	 * saturday and sunday.
	 * </p>
	 */
	public boolean isDayExcluded(int wday) {
		return excludeDays[wday];
	}

	/**
	 * <p>
	 * Determine whether the given time (in milliseconds) is 'included' by the
	 * Calendar.
	 * </p>
	 *
	 * <p>
	 * Note that this Calendar is only has full-day precision.
	 * </p>
	 */
	@Override
	public boolean isTimeIncluded(long timeStamp) {
		if (excludeAll == true) {
			return false;
		}

		// Test the base calendar first. Only if the base calendar not already
		// excludes the time/date, continue evaluating this calendar instance.
		if (super.isTimeIncluded(timeStamp) == false) {
			return false;
		}

		java.util.Calendar cl = createJavaCalendar(timeStamp);
		int wday = cl.get(java.util.Calendar.DAY_OF_WEEK);

		return !(isDayExcluded(wday));
	}

	/**
	 * <p>
	 * Redefine a certain day of the week to be excluded (true) or included
	 * (false). Use java.util.Calendar's constants like MONDAY to determine the
	 * wday.
	 * </p>
	 */
	public void setDayExcluded(int wday, boolean exclude) {
		excludeDays[wday] = exclude;
		excludeAll = areAllDaysExcluded();
	}

	/**
	 * <p>
	 * Redefine the array of days excluded. The array must of size greater or
	 * equal 8. java.util.Calendar's constants like MONDAY should be used as
	 * index. A value of true is regarded as: exclude it.
	 * </p>
	 */
	public void setDaysExcluded(boolean[] weekDays) {
		if (weekDays == null) {
			return;
		}

		excludeDays = weekDays;
		excludeAll = areAllDaysExcluded();
	}
}
